Ion exchange materials are commonly employed to treat and remove ionizable components from fluids for a variety of applications. Flow-through beds or flow-through devices for fluid treatment may employ exchange material or components in the form of grains, fabrics or membranes. The ion exchange functionality operates to transport one type of ion across the material in an electric field, while substantially or effectively blocking most ions of the opposite polarity. Anion exchange polymers and materials carry cationic groups, which repel cations and are selective to anions. Cation exchange polymers and materials carry anionic groups, which repel anions and are selective to cations.
Increasing crosslinking density in ion exchange polymers can improve the mechanical integrity of ion exchange materials prepared from the polymers and reduce water content, but increasing the crosslinking density can also reduce the ion exchange capacity of the material to unacceptable levels.
U.S. Pat. No. 7,968,663, which is incorporated herein by reference, discloses anion exchange polymers prepared from the polymerization of a crosslinked quaternary ammonium monomer (primary crosslinker).
It would be desirable to prepare ion exchange polymers and materials having low water content, increased crosslinking density and good ion exchange capacity for the polymers and materials.